The present invention relates to a watch case comprising a middle at least one opening of which is closed by a bezel and/or a crystal, or by a back, and in which at least one of the elements for closing the opening is linked to the middle by a resilient metal member in the form of a ring or an endless frame and having a recessed cross section defined by the contour of a non-rectilinear wall of controlled thickness whose ends are attached to the periphery of said closing element, respectively of the middle.
It may be advantageous to make the crystal or the back of a watch mobile relative to the middle, and do so without compromising the seal-tightness of the case, for example to improve the impact resistance, or to provide new functions. The solutions proposed in the state of the art are not satisfactory in this respect.
The documents CH630220 and CH686600 describe means for making a crystal move at variable frequencies by means of an electromagnet or a piezoresistive element. Mention is made of a thin annular ring which provides elastic suspension for the crystal. The mobility of the crystal relative to the middle is very limited both in the plane of the crystal and in the plane perpendicular to the crystal, and the seal-tightness is not guaranteed by construction.
CH 632387 and CH 698742 propose forming a resilient link piece between a sound generator and a watch crystal. This link piece is formed by a number of annular segments each having, seen in cross section, a rectilinear form, which has the effect of limiting the amplitude of the mobile piece associated with this link piece.
The document WO 2008027140 describes a mobile (tilting) bezel for activating different functions. The mobility of this bezel is due to a piece made of rubber or of polyurethane, which does not, however, ensure the seal-tightness and whose reliability can be doubted in the long term.